Field
The present disclosure generally relates to articles having vias etched therein. In particular, the present disclosure is directed to articles having vias with a particular geometry, as well as to laser and etching processes for fabricating such articles.
Technical Background
Substrates, such as silicon, have been used as an interposer disposed between electrical components (e.g., printed circuit boards, integrated circuits, and the like). Metalized through-substrate vias provide a path through the interposer for electrical signals to pass between opposite sides of the interposer. Glass is a substrate material that is highly advantageous for electrical signal transmission, as it has dimensional stability, a tunable coefficient of thermal expansion (“CTE”), very good low electrical loss at high frequencies electrical performance, high thermal stability, and an ability to be formed at thickness and at large panel sizes. However, through-glass via (“TGV”) formation and metallization present challenges in development of the glass interposer markets.
Via geometry attributes play a role in the ability for vias within a glass-based substrate to be properly metalized. For example, during a sputter metallization process, the angle of the taper of a side wall of a via may increase the field of view of the via sidewall relative to the sputtered material, which, in turn, prevents the encapsulation of air bubbles against the glass surface and toward the centerline of the via. These air bubbles create processing issues during high temperature redistribution layer (“RDL”) operations and may decrease the reliability of the substrate.
Accordingly, a need exists for substrates having particular via geometries, as well as methods of forming the same.